Boiler



March 7, 1939. o. H. HARTMANN ET M. 2,1 9, 38

BOILER Filed Dec. 30, 193 6 3 Sheets-Sheet 1 flfforney March 1939. O. H.HARTMANN ET AL 2,149,438

BOILER Filed Dec. so, 1956 a Sheets-Sme t 2 h1g E.

Of/v 17 Yaw/07000,

v 170/25 ,Trede A Ivor/7 79.5

March 7, 1939. o. H. HARTMANN ET AL BOILER.

Filed Dec. so, 1936 s Sheets-Sheet 3 ..m w W W My his 03% #fi PatentedMar. 7, 1939 UNITED STATES BOILER Otto H. Hartmann and Hans Trede,Kassel- Wilhelmshohe; Germany Claims. (Cl. 122-332) This invention isdirected to a water tube boiler, and more particularly to marine watertube and similar boilers, and comprises upper and lower headersconnected by a water tube assemblage and radiating pipes which encompassthe combustion chamber, the water tube assemblage forming smoke gasflues. Disposed within the smoke gas flue of the water tube asemblage,are a steam superheater and a feed water preheater, dampers beingprovided to divert the gases of combustion from the smoke flue whendesired.

It is an object of our invention to locate the superheater and the waterpreheater with respect to the tube asemblage so as to obtain aneflicient heating thereof.

It is a further object of our invention to provide means for divertingthe flow of combustion gases with respect to the smoke gas flue when theboiler is being fired, and under other desirable conditions.

In one embodiment of our invention the tubes of the water tubeassemblage are separated in front of the superheater in order to formpassages for the flow of the combustion gases from the combustionchamber into the smoke gas flue, and smoke gas valves or dampers areprovided at such points in order to carry on the combustion gases beforethey reach the superheater.

In another embodiment of our invention the water tube assemblage isprovided with a bypass flue extending parallel with the smoke gas fluehaving the superheater and water preheater, the end of which emptiesinto the smoke gas flue adjacent the feed water preheater and is thereprovided with a regulating valve or dam per. This by-pass flue is formedas a part of the Water tube asemblage.

An air preheater is mounted preferably in an ascending smoke gas flueformed as a part of the water tube assemblage that forms the smoke gasflue carrying the superheater and feed water preheater, so that the airpreheater lies below the upper header of the boiler.

The water tube boiler of the present invention 45 is particularlysuitable for marine purposes because of its simple construction, thefavorable utilization of the heating surfaces therein, and itsrelatively low height. The boiler can be provided with oil, grate orcoal dust firing. It is suitable for indirect as well as direct steamgeneration. Another advantage of its construction consists in providinga particularly simple smoke chimney. This is particularly manifest whentwo boiler sections of the present invention are mounted adjacent eachother so that the flues of each abut and empty into a common chimneyprovided with suitable regulating valves or dampers. -In the indirectproduction of steam the vaporizing drums with the heating elements forthe heat conveyors can be mounted above the chimney. In this manner thepassages for the vaporizing elements to the vaporizing drums are readilyaccessible.

With a double boiler of the precedingly mentioned type the downcomerpipes can be placed at the outside of the boiler, and extend the lengthof the lower and upper headers. As the air preheaters are placed at thecenter of the double boiler the radiation losses of the boiler as wellas of the smoke flues are very small. In addition, this arrangement hasthe advantage in that the air feed passages are very short, with aresultant economy of space and weight. It is also to be noted that thecombustion chamber may be made longer than is usual whereby an excellentcombustion of the fuel may be obtained.

Two embodiments of the invention are illustrated on the accompanyingdrawings, wherein: Fig. 1 is a transverse sectional view of a gratefired type of boiler with the left side shown in section, and

Fig. 2 is a sectional ,view of a modified type of boiler, and isarranged for oil firing.

Fig. 3 is a front elevational view of the boiler shown in Fig. 1.

The upper headers l and the lower headers 2 of I the boiler areconnected by a water tube assemblage 3 as well as by the radiating tubesd. The tubes 3 and 4 are arranged so that the combustion chamber 5 withthe grate 6 is encompassed by them. The water tube assemblage 3 isconstructed so as to form a downwardly extending smoke gas flue 3' andto receive in said flue a steam superheater i and a feed water preheater8. An upwardly directed flue 9 with an air preheater l0 therein isconnected to the downwardly extending flue at the lower end thereof. Asmoke gas valve or damper i2 is placed past the air preheater HI and inthe chimney H. A boiler section of the described arrangement isconstructed together with a similar boiler section so that the flues 9with the air preheaters H] lie directly adjacent each other, beingseparated only by a wall l3.

For permitting the passage of the smoke gases through the water tubeassemblage 3, the flue 3' and the air pre-heater flue 9, the tubes ofthe assemblage 3 are spread apart at their upper ends adjacent the topof the furnace. The tubes that form a wall between the flues 3' and 9are spaced apart at their lower ends to form an opening between theflues.

In a passage it connecting the chimney l l with the upper end of theflue 3 is a smoke gas damper i5, which is normally closed. With thedamper i5 closed the smoke gases flow through the water tube nest 3 fromthe top of the combustion chamber downwardly through the flue 3 and intothe air preheating flue 9 from the bottom thereof upwardly to thechimney El and the stack H5, in which a. suction draft fan I1 ismounted. If, on the contrary, damper l5 is opened, the smoke gasesrising from the furnace 5 pass through the open damper it directly intochimney H and stack E5. The superheater and preheater are then cut out.The smoke gas damper 15, as illustrated, is normally pressed by acounterweight l8 onto a stationary frame I9. It is. rotatably journalledso that it can swing upwardly. Thus when pressure exceeding an allowabledegree arises in the boiler flues, for example through steam escapingfrom a leaky or exploded water tube, the damper I5 is automaticallyopened and the steam can pass off directly through the chimney. Thisdamper then acts as an explosion safety valve.

A further advantage of arranging the smoke gas dampers l5 at the upperends of the connecting passages It consists in that the superheater andthe preheater in the flue 3 are protected from excessive heating andfrom burning by residual smoke gases accumulating in passage M'duringnormal operation of the boiler.

A still further advantage of having the dampers 95 so arranged consistsin that they may be opened so as to create a substantially direct draftfrom the chamber 5 to the chimney I! when the boilers are being fired orstarted up.

In the embodiment of Figs. 1 and 3 a boiler for generating steamindirectly is illustrated.

Provided in the tube system is a heat carrier, for

example water, which is vaporized into steam by the heat of the furnace.The steam rises from the upper headers I through pipes 39 into theheating element 20 located in the water chamber of the vaporizing drums2| through pipes 31. The condensate of the heating steam flows back intoheaders i. As shown on the drawings, the vaporizing drums 2i aredisposed above the chimney l I. The passages of the vaporizing elements38 and SI to the vaporizing drums 2! are thereby easily accessible.

In the embodiment of Fig. 2 the construction of the boiler itself isfundamentally the same as in that of Fig. 1 and similar referencecharacters refer to similar parts. Instead of the grate furnace 6 theboiler of Fig. 2 is fired through oil burners 22, and for regulating thepassage of the smoke gases a by-pass flue 23 is arranged parallel withthe flue 3 in the assemblage 3 which carries the superheater l and thefeed water preheater 8. By-pass 23 is formed by abutting tubes of theassemblage 3, said tubes being spaced at points to provide passage waysfor the smoke gases. The water tube assemblage 3 is covered at the upperend of the combustion chamber to be separated from the smoke flue II.The bypass flue 23 is provided at its lower outlet end into flue 3' witha smoke gas damper 24 which in one position closes off the outlet ofby-pass flue 23, so that the smoke gases will pass from the combustionchamber 5 downwardly through the water tube assemblage 3 with the superheater 1 and the feed water preheater 8 therein and then upwardlythrough the ascending flue 9 with the air preheater ID. If, on thecontrary, damper 24 is opened the superheater l is cut out. The

smoke gases then pass downwardly through the pass flue or through theflue with the superheater.

Similar to the damper if: of Fig. 1, the damper 24 also lies at a pointin which it is protected from burning. Thus, the by-pass flue 23 in theclosed position of damper 24 is filled with stagnant smoke: gases, andthe smoke gases which flow by the damper in the flue 3' are cooledsufficiently by the water heating surfaces and superheater surfacesinterposed in front thereof. In the open position of the damper E l, onthe other hand, the smoke gases in the combustion chamber and adjacentthe water heating surfaces of the bypass flue 23 are cooled to suchdegree as to preclude injurious action to damper 2 Even when thesuperheater is cut out by using the by-pass flue a large heating surfaceis maintained with tube assemblage 3 for the smoke gas currents. Inaddition, the smoke gases flow through the .by-pass flue 23 with agreater velocity than through the flue with the superheater, so thatexcellent heat transmission is obtained even when the superheater is cutout.

It is also to be noted that when use is made of one or more doubleboilers constructed according to our invention, various operativepossibilities are easily carried out; for example, with a double boiler,one boiler section may be cut out for cleaning, repairs, or the like.The other boiler section can then be forced somewhat so that theapproximate normal efficiency of the system can be maintained. Again,with small loads one or more boilers can always be held in reserve. Theuse of the present boiler is also advantageous in harbor operations asthe otherwise necessary auxiliary boiler can be dispensed with, as oneor more of the boiler sections can always be maintained in operation.

The burners can also be disposed in the upper part of the combustionchamber, which would necessitate the superheater and feed waterpreheater being placed in an ascending flue. The by-pass flue can alsobe located at the side of the water tube assemblage adjacent the wallseparating the flues 3' and 9. Finally, the dampers l5 and the dampers23 both can be disposed on one boiler, thus further increasing thesafety of operation and regulability of superheating.

We claim:

1. A marine water tube boiler having an upper and a lower header, watertubes connecting said headers and being constructed and arranged to forma combustion chamber and a downwardly directed flue for smoke exhaustgases adjoining said chamber, a steam superheater and a feed waterpreheater in said flue, and meansassociated with said flue for divertingsaid gases from said superheater when desired.

2. A marine water tube boiler having upper and lower headers connectedby a water tube assemblage and radiating tubes which together, encompassa combustion chamber, said tube assemblage constructed and arranged toform a downwardly extending flue and a side of an upwardly extendingflue, said downwardly extending flue opening into the combustion chamberadjacent its upper end, a steam superheater and feed water preheaterarranged successively within the downwardly extending flue, and meanscooperating with said flues to divert the smoke gases from thesuperheater when desired.

3. A marine water tube boiler as in claim 1, said tubes forming saidflue being separated to form a bypass flue extending parallel to theflue with said superheater, and said means comprising dampers fordiverting said gases from said smoke gas flue to said bypass flue.

4. A marine tube boiler as in claim 1, said tubes being arranged to forma by-pass flue extending parallel to the flue with said superheater,said bypass flue terminating adjacent said feed water preheater, andsaid means connected to said bypass flue whereby said smoke gases may bediverted from said superheater.

5. A marine water tube boiler having two sections, each section havingupper and lower headers connected by radiating tubes and a tubeassemblage which encompass a combustion chamber, each tube assemblagebeing constructed and arranged to form a downwardly directed flue and atleast one side of an upwardly directed flue, a wall and a chimney commonto both sections, each flue emptying into said chimney, each upwardlydirected flue abutting said common wall, each downwardly directed fluehaving a superheater and a water preheater therein, and a damper locatedadjacent the upper end of each upwardly directed flue.

OTTO H. HARTMANN. HANS TREDE.

